lower GIT bleeding

introduction

bright red bleeding not mixed with stool after bowel actions which is present on the toilet bowel and/or toilet paper which resolves soon after and is not associated with haemodynamic instability is most likely to be haemorrhoidal in nature and benign. Anal pain on passage of stool may be due to associated anal fissure or complication of haemorrhoid such as thrombosis or prolapsed haemorrhoid.
non-haemorrhoidal lower GIT bleeding accounts for 20-30% of GIT bleeding cases.
advances in diagnostic and therapeutic colonoscopy and in interventional angiography have resulted in a shift away from the need for surgical treatment.

diverticulitis is the most common cause in Western cultures and may present as sudden painless onset of bright red or wine colored stools which may result in massive bleeding but which usually resolves.
angiodysplasia is by far the most common vascular anomaly found in the GIT with most lesions being in the proximal colon and usually results in less vigorous bleeding than with diverticulosis as it is venocapillary in origin, but without treatment, 80% of patients will have recurrences.
ischaemic colitis is rarely a cause of significant blood loss
radiation colitis may result in mucosal telangiectasias which can bleed.
colorectal cancer (bowel cancer) or polyps accounts for 10% of cases in those aged over 50years, but bleeding is isually low grade and recurrent
infectious colitis such as Salmonella, Campylobacter
other causes include HIV / AIDS, aspirin (acetylsalicylic acid), non-steroidal anti-inflammatory drugs (NSAIDs), inflammatory bowel disease (IBD), polyarteritis nodosa (PAN) and other vasculitides

exclude simple haemorrhoidal bleeding as the cause - this can usually be Mx with reassurance, stool softeners and r/v by LMO
if patient is on warfarin, consider reversing warfarin if bleeding is heavy
if patient is on clopidogrel, consider platelet transfusion
iv line
bloods for FBE, U&E, coags, group and hold
iv fluids to Mx volume loss as indicated
if likely to be an infectious colitis, Mx as for gastroenteritis
erect CXR to exclude perforation diverticulum
PR exam - if melaena, Mx as for upper GIT bleeding, also elderly women may mistake PV bleeding for rectal bleeding and thus a VE may be indicated to rule this possibility out.
hourly vital signs and bowel chart as well as fluid balance chart
contact surgical team ASAP, particularly if heavy bleeding
if Hb < 90 or patient is unstable haemodynamically, then transfuse with 2 units RBC's, and then as needed.
repeat Hb at 6 hours
if ongoing bleeding:
- consider RBC scan or CT angiography to identify bleeding point and if positive, consider surgical intervention (eg. most liekly a total colectomy) or embolisation
- patient is likely to need HDU or potentially ICU admission
if bleeding settles:
- admit for observation and then inpatient or outpatient colonoscopy